1. Technical Field
The present invention relates generally to human lamin A targeted antisense compounds.
2. Description of the Related Art
Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disorder characterized by premature arteriosclerosis and degeneration of vascular smooth muscle cells (SMCs). HGPS manifests itself most notably as accelerated, premature aging in affected children. Children with HGPS have progressive symptoms such as growth retardation, alopecia, loss of subcutaneous fat, and bone abnormalities. Average lifespan is 12 years with the most common cause of death being myocardial infarction or stroke.
Most HGPS cases are caused by a single-point mutation in the lamin A (LMNA) gene, resulting in the generation of progerin, a truncated splicing mutant of lamin A. The single-point mutation is a de novo silent substitution (1824C>T, Gly608Gly) in exon 11 of the lamin A (LMNA) gene. The substitution activates a cryptic splice donor site, which leads to the production of a dominant negative mutant lamin A protein with an internal deletion of 50 amino acids. The mutant protein, named progerin, accumulates on the nuclear membrane, causing characteristic nuclear blebbing ((Scaffidi and Misteli 2005; Cao, Blair et al. 2011)).
It is known that aberrant splicing can be corrected using phosphorodiamidate morpholino oligonucleotides (PMOs), or more specifically, splice-switching oligonucleotides (SSOs). SSOs block aberrant splicing sites by hybridizing at or near the sites thereby preventing recognition by the cellular splicing machinery. Preferred SSOs are resistant to nucleases and the resulting double-stranded structure eliminates the possibility of RNA cleavage by RNase H. SSOs have been shown to effectively repair the splicing pattern both in vitro and in vivo for thalassemia and Duchenne muscular dystrophy. (Kinali, Arechavala-Gomeza et al. 2009; Svasti, Suwanmanee et al. 2009). The aberrant splicing of LMNA associated with HGPS has been shown to be reduced by correction of the aberrant splicing event using modified antisense oligonucleotides targeted to the activated cryptic splice site both in cell culture (Scaffidi and Misteli 2005) and in a relevant animal model (Osorio, Navarro et al. 2011).
Given the role of LMNA in HGPS, oligonucleotides that modulate splicing of LMNA pre-mRNA to eliminate expression of progerin are needed.